Steel work pieces, such as roller bearing parts, are subject to stringent demands with respect to strength, length of use and microscopic structural stability against aging. These work pieces require a material that in the machined state has a homogeneous microstructure with super finely-distributed globular carbides.
In order for a homogeneous microscopic structure to be achieved after heat treatment, the melting can be controlled in a special way in the manufacture of the material. This necessitates major effort and expense with respect to monitoring and control devices. It is also known to homogenize the microscopic structure after the melting annealing is performed. As a rule, this annealing extends over several hours.
Especially stringent demands are made of roller bearings intended for use in transmissions because the transmission oil that is used to lubricate the roller bearings becomes contaminated by metal abrasion. It has therefore been proposed that these bearings be sealed off or at least provided with an oil filter that is intended to keep the metal particles from reaching the interior of the bearing and in particular the races. It is also known to carbonitride these bearings. All of the provisions at present entail major effort and expense and are thus not particularly advantageous in practice.
A need thus exists for a method which, in a simple and relatively inexpensive way, achieves homogeneity of the material in the microscopic range and realization of a refinement of the globular carbides, thus allowing work pieces having such characteristics to be used in a variety of contexts, particularly under extreme conditions such as in roller bearings.